implemented native share intent support for android and ios with chat and folder pickers

lib/state/app/modules/files/bloc/files_bloc.dart

@@ -1,3 +1,5 @@
+import 'package:collection/collection.dart';
+
 import '../../../../../api/errors/error_mapper.dart';
 import '../../../../../api/marianumcloud/webdav/queries/list_files/list_files_response.dart';
 import '../../../infrastructure/loadable_state/loading_error.dart';
@@ -53,12 +55,24 @@ class FilesBloc
   Future<void> _query(List<String> path) async {
     final pathString = path.isEmpty ? '/' : path.join('/');
 
+    // Drop late results when [setPath] has navigated elsewhere or when the
+    // bloc has been disposed (e.g. share-flow picker closed mid-fetch). Both
+    // would otherwise corrupt state or hit "add after close" on the stream.
+    const pathEquality = ListEquality<String>();
+    bool isStale() {
+      if (isClosed) return true;
+      final inner = innerState;
+      if (inner == null) return false;
+      return !pathEquality.equals(inner.currentPath, path);
+    }
+
     Object? capturedError;
     ListFilesResponse? listing;
     try {
       listing = await repo.data.listFiles(
         pathString,
         onCacheData: (cached) {
+          if (isStale()) return;
           // Cached payload arrives before the network call settles. Surface it
           // immediately via Emit so the listing is visible while isLoading
           // stays true and the top loading bar keeps spinning.
@@ -73,6 +87,8 @@ class FilesBloc
       capturedError = e;
     }
 
+    if (isStale()) return;
+
     if (listing != null) {
       listing.files.removeWhere(
         (file) => file.name.isEmpty || file.name == path.lastOrNull,